1. Field of the Invention
The present invention relates generally to integrated circuits and, more particularly, to integrated circuits implementing temperature sensors.
2. Description of the Related Art
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
As most people are aware, an integrated circuit is a highly miniaturized electronic circuit that is typically designed on a semiconductive substrate. Over the last 10 years, considerable attention has been paid to designing smaller, lower-power integrated circuits. These smaller, lower-power integrated circuits are often used in portable electronic devices that rely on battery power, such as cellular phones and laptop computers. As circuit designers research new ways to lower the power consumption of integrated circuits, they are constantly confronted with new challenges that need to be overcome in order to create the integrated circuits that will be part of the next generation of portable devices, such as computers, cellular phones, or cameras.
In many types of integrated circuits, it may be advantageous to accurately measure the temperature of the integrated circuit. One example of this type of integrated circuit is a dynamic random access memory (“DRAM”) circuit. DRAM circuits store information in the form of a capacitive charge on a capacitor. If the charge on the capacitor is greater than a certain threshold, the capacitor may be deemed to store a one. Conversely, if the charge is less than a certain threshold, the capacitor may be deemed to store a zero. In this way, ones and zeros may be electronically stored on a grid of capacitors located within the DRAM. Unfortunately, these capacitors tend to lose their charges over time. As such, to accurately preserve the ones and zeros stored in the array of capacitors, it may be necessary to periodically refresh the capacitors with new charge, if needed. This periodic refreshing, however, can consume power or battery life. Temperature sensors may be advantageous in a DRAM because the speed at which the capacitors lose charge (i.e., how often the DRAM must be refreshed) is related to the temperature of the DRAM. Specifically, the capacitors within a DRAM tend to lose their charges more quickly when the temperature is higher than when the temperature is lower. By accurately measuring the temperature of the DRAM, it may be possible to alter the refresh rate of the DRAM to correspond to the temperature of the DRAM. This functionality can reduce the power usage of the DRAM.
Unfortunately, the process of fabricating a temperature sensor on the integrated circuit can introduce variation into the temperature sensor. For this reason, it may be advantageous to calibrate the temperature sensor. Traditionally, this calibration was performed manually. For example, a technician may place the temperature sensor into a temperature-controlled testing apparatus and then manually adjust the temperature sensor calibration until the temperature sensor is calibrated. While this method is effective, it is time consuming and may not be desirable for large scale production.
Embodiments of the present invention may address one or more of the problems set forth above.